Modeling and system identification of swing check valve flapper using polyvinylidene difluoride film sensor

In the present work, an effort is made to demonstrate the displacement sensing capability of polyvinylidene difluoride film attached to a mechanical structure. A prototype of a swing check valve has been made and details of calibration of polyvinylidene difluoride film with a laser displacement measuring device are discussed. Deflection measurement of the valve flapper using polyvinylidene difluoride film is presented in detail. Model estimation of the swing valve flapper system is carried out using a system identification tool based on the experimental results. Frequency response of estimated model is compared with that of theoretical model.